This invention relates to document information filing systems for successively recording image information of documents or the like in a storage device and retrieving and reading out given document information among various image information stored in the storage device when required.
Recently, document information filing systems have been developed and put to practical use. According to such document information filing system, each of a great deal of documents or the like is scanned by a scanner to produce document information which are progressively stored in a storage device. The desired document information among the various document information stored in the storage device is retrieved and read out for being reproduced into a visual state by an output device such as a cathode-ray-tube (CRT) display or a copying device.
In such document information filing systems, a plurality of magnetic tape cassettes suitably set in a video tape recorder are called respective files and given respective file names in correspondence to the kinds of classes of the document information stored. Of these files, those of the same kind or class or those related to one another are collectively called a file set. Such file sets are given respective file set names. In other words, the file set name is an upper class name with respect to the file name which is a subordinate class name.
While the number of file sets is increased with increasing document information, there should be no file sets of the same file name. Also, there should be no files of the same file name in one file set.
Further, while various pieces of document information stored in one file are given respective peculiar titles, there should be no different pieces of document information in one file that are given the same title.